winform两个窗体之间的传值。传一个User下面是代码
第一个窗体
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace MyMarket
{
public partial class FrmLogin : Form
{
public FrmLogin()
{
InitializeComponent();
}
private void btnlogin_Click(object sender, EventArgs e)
{
if (CheckPut())
{
SQLHelp sqlh = new SQLHelp();
string sql = "select Count(*) from Users where UserName='"+txtUsername.Text.Trim()+"' and Password='"+txtPwd.Text.Trim()+"'";
// sql = string.Format("{0} {1}",, );
if (sqlh.Login(sql))
{
FrmMain frm = new FrmMain();
frm.Show();
FrmModifyPwd frm1 = new FrmModifyPwd();
// frm1.txtusername = txtUsername.Text.Trim();
//frm1.user.Password = txtPwd.Text.Trim();
this.Hide();
}
else
{
MessageBox.Show("用户名或密码错误");
}
}
else
{
MessageBox.Show("信息不能为空");
}
}
//对文本框的验证
private bool CheckPut()
{
if (txtPwd.Text==""||txtUsername.Text=="")
{
return false;
}
else
{
return true;
}
}
public User GetUser(User user)
{
if (CheckPut())
{
user.UserName = txtUsername.Text.Trim();
user.Password = txtPwd.Text.Trim();
return user;
}
else
{
return null;
}
}
private void btncancel_Click(object sender, EventArgs e)
{
this.Close();
}
}
}
第二个窗体
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace MyMarket
{
public partial class FrmModifyPwd : Form
{
public FrmModifyPwd()
{
InitializeComponent();
}
public string txtusername;
private void btnModify_Click(object sender, EventArgs e)
{
FrmLogin frm=new FrmLogin();
string pwd=txtNewPwd.Text.Trim();
int result=CheckPut();
if (result==1)
{
User user = new User();
if (user.Password!=null)
{
if (user.Password == txtOldPwd.Text)
{
SQLHelp sqlh=new SQLHelp();
string sql = "Update Users set Password='"+pwd+"' where UserName= '"+txtusername+"'";
if (sqlh.ModifyPwd(sql))
{
MessageBox.Show("修改成功");
}
else
{
MessageBox.Show("修改失败");
}
// sql = string.Format("{0},{1}", txtNewPwd, userName);
}
else
{
MessageBox.Show("原密码不正确");
}
}
else
{
MessageBox.Show("原密码不正确");
}
}
if (result==-1)
{
MessageBox.Show("信息不能为空");
}
if (result==-2)
{
MessageBox.Show("两次密码不一致");
}
}
private void btncancel_Click(object sender, EventArgs e)
{
this.Close();
}
//对文本框的验证
private int CheckPut()
{
if (txtConNewpwd.Text==""||txtNewPwd.Text==""||txtOldPwd.Text=="")
{
return -1;
}
else
{
if (txtConNewpwd.Text.Trim()==txtNewPwd.Text.Trim())
{
return 1;
}
else
{
return -2;
}
}
}
}
}
这样传过去的user一直是空值 一直是null